The Indianapolis Motor Speedway and Circuit de Spa-Francorchamps are known more for their open-wheel races than sports car ones. But it’ll be a fleet of prototype and GT cars gracing their hallowed grounds this weekend.

IMS plays host to GRAND-AM’s Rolex Series and Continental Tire Sports Car Challenge on the track’s infield road course, formerly used for Formula One and still used by MotoGP. GRAND-AM was added to the docket last year as part of the inaugural IMS “Super Weekend.” Rolex will run a three-hour race to wrap its three-race North American Endurance Championship, with the Conti series a two-hour, 30-minute affair.

Sebastien Bourdais and Alex Popow (Starworks Motorsport, Daytona Prototype) and Andy Lally and John Potter (Magnus Racing, GT) were the initial Rolex winners, but the race was marred by the second Starworks’ car, driven by Ryan Dalziel and Enzo Potolicchio, taken out by Juan Pablo Montoya in the race.

Meanwhile at Spa, the Blancpain Endurance Series, a popular European championship that features FIA GT3-spec machinery and largely Pro-Am driver lineups, will race the Total 24 Hours of Spa. It’s less heralded than the 24 Hours of Le Mans but still regarded highly by the sports car community.

Consider you have Audi R8s, BMW Z4s, McLaren MP4-12Cs, Nissan GT-Rs, Porsche 911s, Ferrari 458s, Lamborghini LFPs, Mercedes SLS AMG 63s, and Aston Martin Vantages among those racing… and that’s just the first page of the entry list. You can see the full entry list here.